Phosphonic and phosphinic acids and their thio analogues containing a dichlorobenzylthio-ether group



United States Patent 3,185,722 PHOSPHONIC AND PHOSPHINEC ACIDS AND THEIR THHO ANALOGUES CONTAINING A Dil- CHLOROBENZYLTl-HO-ETHER' GROUP Gerhard Schrader, Wuppertal-Cronenberg, Germany, as-

signor to Farbenfabriken p Bayer Aktiengesellschaft, Leverkusen, Germany, a German corporation No Drawing. Filed May 29, 1962, Ser. No. 198,430 Claims priority, applicationliizermany, June 8, 1961,

6 Claims. 61. 260-461) The present invention relates to and has as its objects new and useful insecticidal phosphorus derivatives and processes for the production thereof. Generally the new compounds of this invention may be shown by the following formula In the above formula R and R stand for identical or different, optionally substituted alkyl or alkoxy radicals, preferably with a carbon number of 1 to 6.

It is known that the readily obtainable 3,4-dichlorobenzylchloride can be converted by reaction with B-hydroxyethyl mercaptan into fi-hydroxy-ethyl-El,4-dichlorobenzyl-thio-ether.

(RP. 161 C./2 mm. Hg)

The last mentioned product can be converted by known methods with chlorinating agents into ,B-chloroethyl-SA- dichlorobenzylthioether:

(B.P.: 148 C./1 mm. Hg)

chlorinating agent erably in the presence of an inert organic solvent.

Among the salts of the aforesaid acids, alkali metal and ammonium salts are to be considered in the first place, whilst lower aliphatic ketones or nitriles, such as acetone, methyl-ethyl ketone or acetonitrile are especially suitable. as solvents.

The thioor dithiophosphoric (-phosphonic, -phosphinic) acid esters obtainable according to the process are distinguished by outstanding insecticidal properties and possess, in addition to an excellent contact insecticidal, a markedly systemic activity against a number of insect 3,l85,722 Patented May 25, 1965 pests. Moreover, the products of the process, surprisingly, have a comparatively slight toxic action towards warm-blooded animals.

They very effectively kill insects like flies, mites, aphids, etc. They distinguish themselves especially by a good contact-insecticidal activity and at the same time by an activity on eating insects such as caterpillars.

They may be used in the same manner as other known phosphoric acid insecticides, i.e. in a concentration from about 0.00001% to about 1%, diluted or extended with suitable solid or liquid carriers or diluents.

Examples of such solid carriers are talc, chalk, bentonite, clay and the like, as liquid carriers there may be mentioned water (if necessary with commercial emulsifiers), alcohols, especially lower alcohols such as methanol or ethanol, ketones, especially lower ketones such as acetone or methyl ethyl ketone, liquid hydrocarbons and the like. combination with each other or with known insecticides, fertilizers etc.

As an example for the special utility of the inventive compounds the ester of the following formula soH oH -sCHi -01.

has been tested against aphids and spider mites. Aqueous solutions of the aforementioned compound have been prepared by admixing them with the same amount of an auxiliary solvent (acetone). A commercial emulsifier (benzyl hydroxy diphenyl polyglycol ether) is added in an amount of 20% referred to active ingredient. This premixture then is diluted with water to the desired concentration. The tests have been carried out as follows:

(a) Against aphids of the type Doralis fabae. Heavily infested bean plants (Vicia faba) have been sprayed drip wet with solutions as prepared above and in a concentration as shown below. The effect has been determined after 24 hours by evaluation, counting the dead pests either on the surface of the soil or still remaining on the plants. The following results have been obtained:

Aphids are killed by 0.001% solutions.

([2) Against spider mites. Bean plants (Phaseolus vulgaris) of about 15 inches height are sprayed drip Wet with solutions prepared as indicated above. The bean plants have been infested heavily with the two-spotted spider (species Tetmnychus telarius). Evaluation has been carried out after 24 hours, 48 hours and 8 days. The following results have been obtained:

Spider mites are killed 100% by 0.001% solutions.

The following examples illustrate the process as claimed.

Example 1 64 g. (0.33 mol) of ammonium 0,0-diethylthiol-phosphate are dissolved in 200 cc. of acetonitrile. To this solution 86 g. of ,8-chloroethyl-3,4-dichlorobenzy1 thioether are added at 80 C. with stirring, the reaction mixture is then heated to 80 C. for a further 2 hours and then poured into 400 cc. of ice water. The separated oil is taken up in 300 cc. of benzene, the benzene solution is Washed with water and subsequently dried over sodium sulphate. After the solvent has been distilled off under vacuum, there remain g. (81% of the theoretical) of the ester of the above constitution in form of a pale-yellow to colourless, water-insoluble oil.

The new compounds may furthermore be used in V Analysis.-Calculated for molecular weight 389: Cl, 18.3%; S, 16.4%; P, 8.0%. Found: Cl, 19.8%; S, 16.1%; P, 7.9%.

On rats per os the mean toxicity of the compound amounts to 25 mg. per kg. animal.

Example 2 To a solution of 75 g. (0.33 mol) of potassium 0,0- diethyl-thionothiol phosphate in 100 cc. of methyl-ethyl ketone there are added at 80 C. with stirring 86 g. of ,8- ch1oroethyl-3,4-dichlorobenzyl thioether, the reaction mixture is then heated to 80 C. for a further 2 hours and then poured into 200 cc. of ice water. The separated oil is taken up in 200 cc. of benzene, the benzene solution is washed with water, dried over sodium sulphate and the solvent is distilled ofr' under vacuum. 95 g. (70% of the theoretical) of the above-mentioned ester are obtained in form of a pale-yellow, water-insoluble oil.

Analysis.-Calculated for molecular weight 405: S, 23.7%; P, 7.6%; Cl, 17.5%. Found: S, 22.6%; P, 7.3%; CI, 18.0%.

On rats per os the mean toxicity of the compound amounts to 100 mg. per kg. animal.

When used in a concentration of 0.01%, the preparation still shows a 100% action against spider mites and caterpillars.

Example 3 70 g. (0.33 mol) of potassium ethyl-O-ethylthionothiol- I I/ CgHs-P phosphonate are dissolved in 200 cc. of acetonitrile, 86

g. of B-chloroethyl-3,4-dichlorobenzyl thioether are added to this solution at 80 C. with stirring, the reaction mixture is subsequently heated to 80 C. for 2 hours and worked up as described in Examples 1 and 2. 104 g. 80% of the theoretical) of the ester of the above formula are obtained as a pale-yellow, water-insoluble oil.

ArtaZysis.Calculated for molecular weight 389: C1, 18.2%; S. 24.6%; P, 7.9%. 24.3%; P, 7.0%.

Spider mites are killed 100% by 0.001% solutions of the compound. Against ectoparasites (blowfiies) the preparation is still eiiective in a quantity of p.p.m.

Example 4 A solution of 60 g. (0.33 mol) of potassium methyl- O-methylthionothiol phosphonate in 200 cc. of acetoni- Y caterpillars by 0.01% solutions of the ester.

Example 5 S O 01H; ll 01 CHa-P l 65 g. (0.33 mol) of potassium methyl-O-ethyl-thio- Found: Cl, 17.7%; S,

nothiol-phosphonate are dissolved in 200 cc. of acetonitrile. The resulting solution is treated at C. whilst stirring with 86 g. of ,8-chloroethyl-3,4-dichlorobenzyl thioether, the reaction mixture is heated to 80 C. for a further 2 hours and then worked up as described in Examples 1 and 2. There are obtained g. (84% of the theoretical) of the above esters in form of a pale-yellow, water-insoluble oil.

Analysis.-Calculated for molecular weight 375: C1, 19.0%; P, 8.2%; S, 25.6%. Found: CI, 19.9%; P. 7.9%; S, 24.7%.

On rats per es the mean toxicity (DL of the compound amounts to 10 mg. per kg. animal.

Aphids are killed 50% by 0.001% solutions of the ester.

Example 6 CH3 P To a solution of 59 g. (0.33 mol) of potassium methyl- O-ethyl-thiolphosphonate in 200 cc. of :acetonit-rile 86 g. of B-chloroethyl-S,4-dichlomobenzyl thi-oether are added at 70 to 80 C. with stirring. The reaction mixture is then heated to 75 to 80 C. for 2 hours and then worked up as described in the preceding examples. In manner 97 .g. (81% of the theoretical) of the ester of the above diormula are obtained as a yellow, water-insoluble oil.

Analysis.Calculated for molecular weight 359: C1, 19.8%; P, 8.6%; S, 17.8%. Found: 01, 21.3%; P, 7.3%; S, 17.0%.

Spider mites and aphids are killed 100% by 0.001% solutions of the compounds. 0.1% solutions show a marked systemic action against aphids and spider mites.

Example 7 70 g. (0.33 mol) of potassium dimethylthionothi-ol phosphinate are dissolved in cc. of acetonitrile, the solution is treated at 75 C. whilst stirring with 86 g. of fi-chlonoethyl-3,4-dichl-orobenzyl-thioether, the reaction mixture is subsequently heated to 75 to 80 C. for a further 2 hours and worked up as described in Examples 1 and 2. In this way 102 g. (89% of the theoretical) of the ester of the above constitution are obtained in form of a yellow, water-insoluble oil.

Analysis.Ca;lculated for molecular weight 345: Cl, 20.6%; P, 9.0%; S, 27.8%. Found: Cl, 21.5%; P, 8.3%; S, 27.4% 3

Caterpillars are killed 100% by 0.01% solutions, aphids even by 0.001% solutions of the compound.

Example 8 O 0 01.115 ll 01 C2H5P l 65 g. of potassium ethyl-O-ethyl-thiol-phosphonate are dissolved in 150 cc. of lacetonitril'e. 86 g. of ,B-chloroethyl-3,4-dichloro-benzyl thicether are added to the resulting solution at 80 C. whilst stinring, the reaction mixture is then heated to '80" C. for 2 hours and then worked up as described in Examples 1 land 2. 106 g.

Found: 01, 19.8%; P, 7.8%;

5 I claim: 1. A compound of the following formula:

R1 X I 4. The compound of the following formula wherein R stands for lower valkyl, R stands for :a. member selected from the group consisting of lower alky-land lower alkoxy-radicals and X is a member of the group 10 consisting of Oxygen and sulfur.

2. The eompound of the fiollowing formula 3. The compound of the following formula 5. A compound of claim 1 wherein R and R are each lower alkyl.

6. A compound of claim 1 wherein R is a. lower alkyl and R is a. lower al-koxy. 

1. A COMPOUND OF THE FOLLOWING FORMULA: 